dan chose number three. a year later he also identified o'connell in court. >> i believed they had done their jobs. they had caught the right guy. >> eyewitness identification is a major, major problem in erroneous conviction. >> reporter: a leading forensic expert in eyewitness testimony said six-packs have been proven to be highly fallible. >> the largest source of i.d. is resemblance. >> reporter: is it egregious don't vick somebody on eyewitness testimony? >> without expert testimony yes. >> as a young child you go oh, my dad is innocent. got to be getting out. you get older and you start to realize the system is not designed to correct mistakes. you watch tv and you say that doesn't happen. it does happen. it happened to me. it could happen to anybody. >> troy roberts joins us at the table. how strong of a witness is dan drucker? >> wasn't very strong, actually. he only had like two seconds to see the shooter and it was a profile. >> he was so sure though, troy. >> he was so sure. he said he was pressur